Halti did not do anything to give the man any control on the dog - the dog just braced him/herself against the head - collar and and ran across a multi-lane highway dragging his 16 feet behind him hanging on to the handle of the extended leash -

I'm still trying to figure out how a flexi on a halti on a dog that just braces itself and pulls is supposed to provide control?

No idea I saw a similar one where a person threw a prong collar into that mix - head halter and prong both hooked up to the Flexi. I don't know if the prong was actually doing anything at that point, but it didn't make it any less stupid.